<template>
  <div>父组件----{{ num }}---{{ num2 }}
    <!-- v-model只能绑定一次 -->
    <!-- <Son v-model="num" /> -->
    <!-- .sync可以绑定多个 -->
    <hr>
    <Son
      :aa.sync="num"
      :bb.sync="num2"
      @update:aa="val=>num=val"
      @update:bb="val=>num2=val"
    />
    <Son
      :aa.sync="num"
      :bb.sync="num2"
    />
  </div>

</template>
<script>
import Son from './Son.vue'
export default {
  components: {
    Son
  },
  data() {
    return {
      num: 100,
      num2: 200
    }
  }
}
</script>
